1
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Schwartz EA, Bravo JPK, Ahsan M, Macias LA, McCafferty CL, Dangerfield TL, Walker JN, Brodbelt JS, Palermo G, Fineran PC, Fagerlund RD, Taylor DW. RNA targeting and cleavage by the type III-Dv CRISPR effector complex. Nat Commun 2024; 15:3324. [PMID: 38637512 PMCID: PMC11026444 DOI: 10.1038/s41467-024-47506-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 04/02/2024] [Indexed: 04/20/2024] Open
Abstract
CRISPR-Cas are adaptive immune systems in bacteria and archaea that utilize CRISPR RNA-guided surveillance complexes to target complementary RNA or DNA for destruction1-5. Target RNA cleavage at regular intervals is characteristic of type III effector complexes6-8. Here, we determine the structures of the Synechocystis type III-Dv complex, an apparent evolutionary intermediate from multi-protein to single-protein type III effectors9,10, in pre- and post-cleavage states. The structures show how multi-subunit fusion proteins in the effector are tethered together in an unusual arrangement to assemble into an active and programmable RNA endonuclease and how the effector utilizes a distinct mechanism for target RNA seeding from other type III effectors. Using structural, biochemical, and quantum/classical molecular dynamics simulation, we study the structure and dynamics of the three catalytic sites, where a 2'-OH of the ribose on the target RNA acts as a nucleophile for in line self-cleavage of the upstream scissile phosphate. Strikingly, the arrangement at the catalytic residues of most type III complexes resembles the active site of ribozymes, including the hammerhead, pistol, and Varkud satellite ribozymes. Our work provides detailed molecular insight into the mechanisms of RNA targeting and cleavage by an important intermediate in the evolution of type III effector complexes.
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Affiliation(s)
- Evan A Schwartz
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Mohd Ahsan
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, CA, USA
| | - Luis A Macias
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA
| | - Caitlyn L McCafferty
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Tyler L Dangerfield
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Jada N Walker
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA
| | | | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, CA, USA.
| | - Peter C Fineran
- Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Robert D Fagerlund
- Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand.
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin, New Zealand.
- Genetics Otago, University of Otago, PO Box 56, Dunedin, New Zealand.
| | - David W Taylor
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA.
- LIVESTRONG Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
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2
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Krishnan A, Waheed SO, Varghese A, Cherilakkudy FH, Schofield CJ, Karabencheva-Christova TG. Unusual catalytic strategy by non-heme Fe(ii)/2-oxoglutarate-dependent aspartyl hydroxylase AspH. Chem Sci 2024; 15:3466-3484. [PMID: 38455014 PMCID: PMC10915816 DOI: 10.1039/d3sc05974j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 02/02/2024] [Indexed: 03/09/2024] Open
Abstract
Biocatalytic C-H oxidation reactions are of important synthetic utility, provide a sustainable route for selective synthesis of important organic molecules, and are an integral part of fundamental cell processes. The multidomain non-heme Fe(ii)/2-oxoglutarate (2OG) dependent oxygenase AspH catalyzes stereoselective (3R)-hydroxylation of aspartyl- and asparaginyl-residues. Unusually, compared to other 2OG hydroxylases, crystallography has shown that AspH lacks the carboxylate residue of the characteristic two-His-one-Asp/Glu Fe-binding triad. Instead, AspH has a water molecule that coordinates Fe(ii) in the coordination position usually occupied by the Asp/Glu carboxylate. Molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) studies reveal that the iron coordinating water is stabilized by hydrogen bonding with a second coordination sphere (SCS) carboxylate residue Asp721, an arrangement that helps maintain the six coordinated Fe(ii) distorted octahedral coordination geometry and enable catalysis. AspH catalysis follows a dioxygen activation-hydrogen atom transfer (HAT)-rebound hydroxylation mechanism, unusually exhibiting higher activation energy for rebound hydroxylation than for HAT, indicating that the rebound step may be rate-limiting. The HAT step, along with substrate positioning modulated by the non-covalent interactions with SCS residues (Arg688, Arg686, Lys666, Asp721, and Gln664), are essential in determining stereoselectivity, which likely proceeds with retention of configuration. The tetratricopeptide repeat (TPR) domain of AspH influences substrate binding and manifests dynamic motions during catalysis, an observation of interest with respect to other 2OG oxygenases with TPR domains. The results provide unique insights into how non-heme Fe(ii) oxygenases can effectively catalyze stereoselective hydroxylation using only two enzyme-derived Fe-ligating residues, potentially guiding enzyme engineering for stereoselective biocatalysis, thus advancing the development of non-heme Fe(ii) based biomimetic C-H oxidation catalysts, and supporting the proposal that the 2OG oxygenase superfamily may be larger than once perceived.
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Affiliation(s)
- Anandhu Krishnan
- Department of Chemistry, Michigan Technological University Houghton MI 49931 USA
| | - Sodiq O Waheed
- Department of Chemistry, Michigan Technological University Houghton MI 49931 USA
| | - Ann Varghese
- Department of Chemistry, Michigan Technological University Houghton MI 49931 USA
| | | | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford OX1 3TA Oxford UK
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3
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Asgharpour S, Chi LA, Spehr M, Carloni P, Alfonso-Prieto M. Fluoride Transport and Inhibition Across CLC Transporters. Handb Exp Pharmacol 2024; 283:81-100. [PMID: 36042142 DOI: 10.1007/164_2022_593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Chloride Channel (CLC) family includes proton-coupled chloride and fluoride transporters. Despite their similar protein architecture, the former exchange two chloride ions for each proton and are inhibited by fluoride, whereas the latter efficiently transport one fluoride in exchange for one proton. The combination of structural, mutagenesis, and functional experiments with molecular simulations has pinpointed several amino acid changes in the permeation pathway that capitalize on the different chemical properties of chloride and fluoride to fine-tune protein function. Here we summarize recent findings on fluoride inhibition and transport in the two prototypical members of the CLC family, the chloride/proton transporter from Escherichia coli (CLC-ec1) and the fluoride/proton transporter from Enterococcus casseliflavus (CLCF-eca).
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Affiliation(s)
- Somayeh Asgharpour
- Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9, Computational Biomedicine, Forschungszentrum Jülich, Jülich, Germany
- Research Training Group 2416 MultiSenses-MultiScales, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - L América Chi
- Laboratory for the Design and Development of New Drugs and Biotechnological Innovation, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Ciudad de México, Mexico
| | - Marc Spehr
- Research Training Group 2416 MultiSenses-MultiScales, Institute for Biology II, RWTH Aachen University, Aachen, Germany
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany
| | - Paolo Carloni
- Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9, Computational Biomedicine, Forschungszentrum Jülich, Jülich, Germany.
- Research Training Group 2416 MultiSenses-MultiScales, Institute for Biology II, RWTH Aachen University, Aachen, Germany.
- Department of Physics, RWTH Aachen University, Aachen, Germany.
- JARA Institute Molecular Neuroscience and Neuroimaging (INM-11), Forschungszentrum Jülich, Jülich, Germany.
- JARA-HPC, Forschungszentrum Jülich, Jülich, Germany.
| | - Mercedes Alfonso-Prieto
- Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9, Computational Biomedicine, Forschungszentrum Jülich, Jülich, Germany.
- Medical Faculty, Cécile and Oskar Vogt Institute for Brain Research, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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4
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Nin-Hill A, Ardevol A, Biarnés X, Planas A, Rovira C. Control of Substrate Conformation by Hydrogen Bonding in a Retaining β-Endoglycosidase. Chemistry 2023; 29:e202302555. [PMID: 37804517 DOI: 10.1002/chem.202302555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/29/2023] [Accepted: 10/02/2023] [Indexed: 10/09/2023]
Abstract
Bacterial β-glycosidases are hydrolytic enzymes that depolymerize polysaccharides such as β-cellulose, β-glucans and β-xylans from different sources, offering diverse biomedical and industrial uses. It has been shown that a conformational change of the substrate, from a relaxed 4 C1 conformation to a distorted 1 S3 /1,4 B conformation of the reactive sugar, is necessary for catalysis. However, the molecular determinants that stabilize the substrate's distortion are poorly understood. Here we use quantum mechanics/molecular mechanics (QM/MM)-based molecular dynamics methods to assess the impact of the interaction between the reactive sugar, i. e. the one at subsite -1, and the catalytic nucleophile (a glutamate) on substrate conformation. We show that the hydrogen bond involving the C2 exocyclic group and the nucleophile controls substrate conformation: its presence preserves sugar distortion, whereas its absence (e.g. in an enzyme mutant) knocks it out. We also show that 2-deoxy-2-fluoro derivatives, widely used to trap the reaction intermediates by X-ray crystallography, reproduce the conformation of the hydrolysable substrate at the experimental conditions. These results highlight the importance of the 2-OH⋅⋅⋅nucleophile interaction in substrate recognition and catalysis in endo-glycosidases and can inform mutational campaigns aimed to search for more efficient enzymes.
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Affiliation(s)
- Alba Nin-Hill
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) &, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028, Barcelona, Spain
- present address: Toulouse Biotechnology Institute, TBI, Universite de Toulouse, CNRS, INRAE, INSA Toulouse, 135, avenue de Rangueil, 31077, Toulouse Cedex 04, France
| | - Albert Ardevol
- CSIRO Manufacturing, GPO Box 1700, Canberra, ACT 2601, Australia
| | - Xevi Biarnés
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017, Barcelona, Spain
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) &, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08020, Barcelona, Spain
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5
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Kılıç M, Diamantis P, Johnson SK, Toth O, Rothlisberger U. Redox-Based Defect Detection in Packed DNA: Insights from Hybrid Quantum Mechanical/Molecular Mechanics Molecular Dynamics Simulations. J Chem Theory Comput 2023; 19:8434-8445. [PMID: 37963372 PMCID: PMC10687876 DOI: 10.1021/acs.jctc.3c01013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023]
Abstract
The impact of an 8-oxoguanine (8oxoG) defect on the redox properties of DNA within the nucleosome core particle (NCP) was investigated employing hybrid quantum mechanical/molecular mechanics (QM/MM) molecular dynamics simulations of native and 8oxoG-containing NCP systems with an explicit representation of a biologically relevant environment. Two distinct NCP positions with varying solvent accessibility were considered for 8oxoG insertion. In both cases, it is found that the presence of 8oxoG drastically decreases the redox free energy of oxidation by roughly 1 eV, which is very similar to what was recently reported for free native and 8oxoG-containing DNA. In contrast, the effect of 8oxoG on the reorganization free energy is even smaller for packed DNA (decrease of 0.13 and 0.01 eV for defect-free and defect-containing systems, respectively) compared to the one for free DNA (0.25 eV), consistent with the increased rigidity of the NCP as compared to free DNA. Furthermore, the presence of an 8oxoG defect does not yield any significant changes in the packed DNA structure. Such a conclusion favors the idea that in the case of chromatin, defect-induced changes in DNA redox chemistry can also be exploited to detect damaged bases via DNA-mediated hole transfer.
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Affiliation(s)
| | | | - Sophia K. Johnson
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Oliver Toth
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry
and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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6
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Kar R, Mandal S, Thakkur V, Meyer B, Nair NN. Speeding-up Hybrid Functional-Based Ab Initio Molecular Dynamics Using Multiple Time-stepping and Resonance-Free Thermostat. J Chem Theory Comput 2023; 19:8351-8364. [PMID: 37933121 DOI: 10.1021/acs.jctc.3c00964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Ab initio molecular dynamics (AIMD) based on density functional theory (DFT) has become a workhorse for studying the structure, dynamics, and reactions in condensed matter systems. Currently, AIMD simulations are primarily carried out at the level of generalized gradient approximation (GGA), which is at the second rung of DFT functionals in terms of accuracy. Hybrid DFT functionals, which form the fourth rung in the accuracy ladder, are not commonly used in AIMD simulations as the computational cost involved is 100 times or higher. To facilitate AIMD simulations with hybrid functionals, we propose here an approach using multiple time stepping with adaptively compressed exchange operator and resonance-free thermostat, that could speed up the calculations by ∼30 times or more for systems with a few hundred of atoms. We demonstrate that by achieving this significant speed up and making the compute time of hybrid functional-based AIMD simulations at par with that of GGA functionals, we are able to study several complex condensed matter systems and model chemical reactions in solution with hybrid functionals that were earlier unthinkable to be performed.
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Affiliation(s)
- Ritama Kar
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India
| | - Sagarmoy Mandal
- Interdisciplinary Center for Molecular Materials and Computer Chemistry Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstr. 25, Erlangen 91052, Germany
- Erlangen National High Performance Computing Center (NHR@FAU), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 1, Erlangen 91058, Germany
| | - Vaishali Thakkur
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India
| | - Bernd Meyer
- Interdisciplinary Center for Molecular Materials and Computer Chemistry Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstr. 25, Erlangen 91052, Germany
- Erlangen National High Performance Computing Center (NHR@FAU), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstr. 1, Erlangen 91058, Germany
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India
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7
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Peng W, Wang Z, Zhang Q, Yan S, Wang B. Unraveling the Valence State and Reactivity of Copper Centers in Membrane-Bound Particulate Methane Monooxygenase. J Am Chem Soc 2023; 145:25304-25317. [PMID: 37955571 DOI: 10.1021/jacs.3c08834] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Particulate methane monooxygenase (pMMO) plays a critical role in catalyzing the conversion of methane to methanol, constituting the initial step in the C1 metabolic pathway within methanotrophic bacteria. However, the membrane-bound pMMO's structure and catalytic mechanism, notably the copper's valence state and genuine active site for methane oxidation, have remained elusive. Based on the recently characterized structure of membrane-bound pMMO, extensive computational studies were conducted to address these long-standing issues. A comprehensive analysis comparing the quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulated structures with cryo-EM data indicates that both the CuC and CuD sites tend to stay in the Cu(I) valence state within the membrane environment. Additionally, the concurrent presence of Cu(I) at both CuC and CuD sites leads to the significant reduction of the ligand-binding cavity situated between them, making it less likely to accommodate a reductant molecule such as durohydroquinone (DQH2). Subsequent QM/MM calculations reveal that the CuD(I) site is more reactive than the CuC(I) site in oxygen activation, en route to H2O2 formation and the generation of Cu(II)-O•- species. Finally, our simulations demonstrate that the natural reductant ubiquinol (CoQH2) assumes a productive binding conformation at the CuD(I) site but not at the CuC(I) site. This provides evidence that the true active site of membrane-bound pMMOs may be CuD rather than CuC. These findings clarify pMMO's catalytic mechanism and emphasize the membrane environment's pivotal role in modulating the coordination structure and the activity of copper centers within pMMO.
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Affiliation(s)
- Wei Peng
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, P. R. China
- Key Laboratory of Aerosol Chemistry and Physics, State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, P. R. China
| | - Zikuan Wang
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Qiaoyu Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, P. R. China
| | - Shengheng Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, P. R. China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, P. R. China
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8
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Diao W, Farrell JD, Wang B, Ye F, Wang Z. Preorganized Internal Electric Field Promotes a Double-Displacement Mechanism for the Adenine Excision Reaction by Adenine DNA Glycosylase. J Phys Chem B 2023; 127:8551-8564. [PMID: 37782825 DOI: 10.1021/acs.jpcb.3c04928] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Adenine DNA glycosylase (MutY) is a monofunctional glycosylase, removing adenines (A) misinserted opposite 8-oxo-7,8-dihydroguanine (OG), a common product of oxidative damage to DNA. Through multiscale calculations, we decipher a detailed adenine excision mechanism of MutY that is consistent with all available experimental data, involving an initial protonation step and two nucleophilic displacement steps. During the first displacement step, N-glycosidic bond cleavage is accompanied by the attack of the carboxylate group of residue Asp144 at the anomeric carbon (C1'), forming a covalent glycosyl-enzyme intermediate to stabilize the fleeting oxocarbenium ion. After departure of the excised base, water nucleophiles can be recruited to displace Asp144, completing the catalytic cycle with retention of stereochemistry at the C1' position. The two displacement reactions are found to mostly involve the movement of the oxocarbenium ion, occurring with large charge reorganization and thus sensitive to the internal electric field (IEF) exerted by the polar protein environment. Intriguingly, we find that the negatively charged carboxylate group is a good nucleophile for the oxocarbenium ion, yet an unactivated water molecule is not, and that the electric field catalysis strategy is used by the enzyme to enable its unique double-displacement reaction mechanism. A strong IEF, pointing toward 5' direction of the substrate sugar ring, greatly facilitates the second displacement reaction at the expense of elevating the barrier of the first one, thereby allowing both reactions to occur. These findings not only increase our understanding of the strategies used by DNA glycosylases to repair DNA lesions, but also have important implications for how internal/external electric field can be applied to modulate chemical reactions.
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Affiliation(s)
- Wenwen Diao
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325000, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - James D Farrell
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Fangfu Ye
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325000, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325000, China
| | - Zhanfeng Wang
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
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9
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Rastogi S, Chandra A. Free Energy Landscapes of the Tautomeric Interconversion of Pyridoxal 5'-Phosphate Aldimines at the Active Site of Ornithine Decarboxylase in Aqueous Media. J Phys Chem B 2023; 127:8139-8149. [PMID: 37721415 DOI: 10.1021/acs.jpcb.3c04142] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
The pyridoxal 5'-phosphate (PLP) acts as a coenzyme for a large number of biochemical reactions. It exists in mainly two bound forms at the active site of the concerned enzyme: the internal aldimine, in which the PLP is bound with the ϵ-amino group of lysine at the active site, and the external aldimine, where the PLP is bound to the substrate amino acid. Both the internal and external aldimines have Schiff base linkage (N-H-O) and can exist in two tautomeric structures of ketoenamine and enolimine forms. In this work, we have investigated the free energy landscape for the tautomeric proton transfer in the internal and external aldimines at the active site of the ornithine decarboxylase enzyme in an aqueous medium. We performed hybrid quantum-classical metadynamics and force field-based molecular dynamics simulations, which revealed that the ketoenamine tautomer is more stable than the enolimine form. The QM/MM metadynamics calculations show that the free energy difference between the ketoenamine and enolimine forms for the internal aldimine is 3.9 kcal/mol, and it is found to be 5.8 kcal/mol for the external aldimine, with the ketoenamine form being more stable in both cases. The results are further supported by calculations of the binding free energies from classical simulations and static quantum chemical calculations in different environments. We have also analyzed the configurational structure of the microenvironment at the active site in order to have better insights into the interactions of the active site residues with the PLP in its two tautomeric forms.
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Affiliation(s)
- Shreya Rastogi
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
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10
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Jansen M, Reinholdt P, Hedegård ED, König C. Theoretical and Numerical Comparison of Quantum- and Classical Embedding Models for Optical Spectra. J Phys Chem A 2023. [PMID: 37399130 DOI: 10.1021/acs.jpca.3c02540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Quantum-mechanical (QM) and classical embedding models approximate a supermolecular quantum-chemical calculation. This is particularly useful when the supermolecular calculation has a size that is out of reach for present QM models. Although QM and classical embedding methods share the same goal, they approach this goal from different starting points. In this study, we compare the polarizable embedding (PE) and frozen-density embedding (FDE) models. The former is a classical embedding model, whereas the latter is a density-based QM embedding model. Our comparison focuses on solvent effects on optical spectra of solutes. This is a typical scenario where super-system calculations including the solvent environment become prohibitively large. We formulate a common theoretical framework for PE and FDE models and systematically investigate how PE and FDE approximate solvent effects. Generally, differences are found to be small, except in cases where electron spill-out becomes problematic in the classical frameworks. In these cases, however, atomic pseudopotentials can reduce the electron-spill-out issue.
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Affiliation(s)
- Marina Jansen
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3A, 30167 Hannover, Germany
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
| | - Erik D Hedegård
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
| | - Carolin König
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3A, 30167 Hannover, Germany
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11
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Raghavan B, Paulikat M, Ahmad K, Callea L, Rizzi A, Ippoliti E, Mandelli D, Bonati L, De Vivo M, Carloni P. Drug Design in the Exascale Era: A Perspective from Massively Parallel QM/MM Simulations. J Chem Inf Model 2023. [PMID: 37319347 DOI: 10.1021/acs.jcim.3c00557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The initial phases of drug discovery - in silico drug design - could benefit from first principle Quantum Mechanics/Molecular Mechanics (QM/MM) molecular dynamics (MD) simulations in explicit solvent, yet many applications are currently limited by the short time scales that this approach can cover. Developing scalable first principle QM/MM MD interfaces fully exploiting current exascale machines - so far an unmet and crucial goal - will help overcome this problem, opening the way to the study of the thermodynamics and kinetics of ligand binding to protein with first principle accuracy. Here, taking two relevant case studies involving the interactions of ligands with rather large enzymes, we showcase the use of our recently developed massively scalable Multiscale Modeling in Computational Chemistry (MiMiC) QM/MM framework (currently using DFT to describe the QM region) to investigate reactions and ligand binding in enzymes of pharmacological relevance. We also demonstrate for the first time strong scaling of MiMiC-QM/MM MD simulations with parallel efficiency of ∼70% up to >80,000 cores. Thus, among many others, the MiMiC interface represents a promising candidate toward exascale applications by combining machine learning with statistical mechanics based algorithms tailored for exascale supercomputers.
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Affiliation(s)
- Bharath Raghavan
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics, RWTH Aachen University, Aachen 52074, Germany
| | - Mirko Paulikat
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Katya Ahmad
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Lara Callea
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Andrea Rizzi
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Atomistic Simulations, Italian Institute of Technology, Genova 16163, Italy
| | - Emiliano Ippoliti
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Davide Mandelli
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Laura Bonati
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Marco De Vivo
- Molecular Modelling and Drug Discovery, Italian Institute of Technology, Genova 16163, Italy
| | - Paolo Carloni
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics and Universitätsklinikum, RWTH Aachen University, Aachen 52074, Germany
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12
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Das CK, Gupta A, Nair NN. Probing the general base for DNA polymerization in telomerase: a molecular dynamics investigation. Phys Chem Chem Phys 2023; 25:14147-14157. [PMID: 37162325 DOI: 10.1039/d3cp00521f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Telomerase is an RNA-dependent DNA polymerase that plays a role in the maintenance of the 3' end of the eukaryotic chromosome, known as a telomere, by catalyzing the DNA polymerization reaction in cancer and embryonic stem cells. The detailed molecular details of the DNA polymerization by telomerase, especially the general base for deprotonating the terminal 3'-hydroxyl, which triggers the chemical reaction, remain elusive. We conducted a computational investigation using hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations to probe the detailed mechanism of the reaction. Our simulations started with the telomerase:RNA:DNA:dNTP ternary complex, and by using enhanced sampling QM/MM MD simulations, we probed the general base involved directly in the polymerization. We report the participation of an aspartate (Asp344) coordinated to Mg and an active site water molecule, jointly acting as a base during nucleic acid addition. The Asp344 residue remains transiently protonated during the course of the reaction, and later it deprotonates by transferring its proton to the water at the end of the reaction.
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Affiliation(s)
- Chandan Kumar Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Abhinav Gupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
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13
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Pengthaisong S, Piniello B, Davies GJ, Rovira C, Ketudat Cairns JR. Reaction Mechanism of Glycoside Hydrolase Family 116 Utilizes Perpendicular Protonation. ACS Catal 2023; 13:5850-5863. [PMID: 37180965 PMCID: PMC10167657 DOI: 10.1021/acscatal.3c00620] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/15/2023] [Indexed: 05/16/2023]
Abstract
Retaining glycoside hydrolases use acid/base catalysis with an enzymatic acid/base protonating the glycosidic bond oxygen to facilitate leaving-group departure alongside attack by a catalytic nucleophile to form a covalent intermediate. Generally, this acid/base protonates the oxygen laterally with respect to the sugar ring, which places the catalytic acid/base and nucleophile carboxylates within about 4.5-6.5 Å of each other. However, in glycoside hydrolase (GH) family 116, including disease-related human acid β-glucosidase 2 (GBA2), the distance between the catalytic acid/base and the nucleophile is around 8 Å (PDB: 5BVU) and the catalytic acid/base appears to be above the plane of the pyranose ring, rather than being lateral to that plane, which could have catalytic consequences. However, no structure of an enzyme-substrate complex is available for this GH family. Here, we report the structures of Thermoanaerobacterium xylanolyticum β-glucosidase (TxGH116) D593N acid/base mutant in complexes with cellobiose and laminaribiose and its catalytic mechanism. We confirm that the amide hydrogen bonding to the glycosidic oxygen is in a perpendicular rather than lateral orientation. Quantum mechanics/molecular mechanics (QM/MM) simulations of the glycosylation half-reaction in wild-type TxGH116 indicate that the substrate binds with the nonreducing glucose residue in an unusual relaxed 4C1 chair at the -1 subsite. Nevertheless, the reaction can still proceed through a 4H3 half-chair transition state, as in classical retaining β-glucosidases, as the catalytic acid D593 protonates the perpendicular electron pair. The glucose C6OH is locked in a gauche, trans orientation with respect to the C5-O5 and C4-C5 bonds to facilitate perpendicular protonation. These data imply a unique protonation trajectory in Clan-O glycoside hydrolases, which has strong implications for the design of inhibitors specific to either lateral protonators, such as human GBA1, or perpendicular protonators, such as human GBA2.
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Affiliation(s)
- Salila Pengthaisong
- School
of Chemistry, Institute of Science, Suranaree
University of Technology, Nakhon
Ratchasima 30000, Thailand
- Center
for Biomolecular Structure, Function and Application, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Beatriz Piniello
- Departament
de Quımica Inorgánica i Orgànica (Secció
de Química Orgànica) and Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Gideon J. Davies
- Department
of Chemistry, University of York, Heslington, York YO10
5DD, U.K.
| | - Carme Rovira
- Departament
de Quımica Inorgánica i Orgànica (Secció
de Química Orgànica) and Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avancats (ICREA), 08010 Barcelona, Spain
| | - James R. Ketudat Cairns
- School
of Chemistry, Institute of Science, Suranaree
University of Technology, Nakhon
Ratchasima 30000, Thailand
- Center
for Biomolecular Structure, Function and Application, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
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14
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Murugan NA, Zaleśny R. Computational Investigations into Two-Photon Fibril Imaging Using the DANIR-2c Probe. J Phys Chem B 2023; 127:3119-3125. [PMID: 37015058 PMCID: PMC10108348 DOI: 10.1021/acs.jpcb.2c07783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
The design of novel fibril imaging molecules for medical diagnosis requires the simultaneous optimization of fibril-specific optical properties and binding specificity toward amyloid fibrils. Because of the possibility to monitor internal organs and deep tissues, the two-photon probes that can absorb in the infrared (IR) and near-IR (NIR) region with a significant two-photon absorption cross section are of immense interest. To contribute to this exploration of chemical compounds suitable for two-photon fibril imaging, we have computationally studied the one- and two-photon properties of a donor-acceptor-substituted DANIR-2c probe, which was used for in vivo detection of β-amyloid deposits using fluorescence spectroscopy. In particular, a multiscale computational approach was employed involving molecular docking, molecular dynamics, hybrid QM/MM molecular dynamics, and coupled-cluster/MM to study the binding of the studied probe to amyloid fibril and its one- and two-photon absorption properties in the fibrillar environment. Multiple binding sites are available for this probe in amyloid fibril, and the one corresponding to the largest binding affinity exhibits also the largest and experimentally meaningful two-photon absorption cross section, thus demonstrating the potential of the studied probe in two-photon microscopy.
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Affiliation(s)
- N Arul Murugan
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi 110020, India
| | - Robert Zaleśny
- Faculty of Chemistry, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, PL-50370 Wrocław, Poland
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15
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Alfonso-Prieto M, Cuxart I, Potocki-Véronèse G, André I, Rovira C. Substrate-Assisted Mechanism for the Degradation of N-Glycans by a Gut Bacterial Mannoside Phosphorylase. ACS Catal 2023. [DOI: 10.1021/acscatal.3c00451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- Mercedes Alfonso-Prieto
- Departament de Química Inorgànica i Orgànica and Institute of Theoretical and Computational Chemistry (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Irene Cuxart
- Departament de Química Inorgànica i Orgànica and Institute of Theoretical and Computational Chemistry (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Gabrielle Potocki-Véronèse
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 04, France
| | - Isabelle André
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRAE, INSA, 135 Avenue de Rangueil, F-31077 Toulouse Cedex 04, France
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica and Institute of Theoretical and Computational Chemistry (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
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16
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Dutta S, Chandra A. A Multiple Proton Transfer Mechanism for the Charging Step of the Aminoacylation Reaction at the Active Site of Aspartyl tRNA Synthetase. J Chem Inf Model 2023; 63:1819-1832. [PMID: 36893463 DOI: 10.1021/acs.jcim.2c01332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Aspartyl-tRNA synthetase catalyzes the attachment of aspartic acid to its cognate tRNA by the aminoacylation reaction during the initiation of the protein biosynthesis process. In the second step of the aminoacylation reaction, known as the charging step, the aspartate moiety is transferred from aspartyl-adenylate to the 3'-OH of A76 of tRNA through a proton transfer process. We have investigated different pathways for the charging step through three separate QM/MM simulations combined with the enhanced sampling method of well-sliced metadynamics and found out the most feasible pathway for the reaction at the active site of the enzyme. In the charging reaction, both the phosphate group and the ammonium group after deprotonation can potentially act as a base for proton transfer in the substrate-assisted mechanism. We have considered three possible mechanisms involving different pathways of proton transfer, and only one of them is determined to be enzymatically feasible. The free energy landscape along reaction coordinates where the phosphate group acts as the general base showed that, in the absence of water, the barrier height is 52.6 kcal/mol. The free energy barrier is reduced to 39.7 kcal/mol when the active site water molecules are also treated quantum mechanically, thus allowing a water mediated proton transfer. The charging reaction involving the ammonium group of the aspartyl adenylate is found to follow a path where first a proton from the ammonium group moves to a water in the vicinity forming a hydronium ion (H3O+) and NH2 group. The hydronium ion subsequently passes the proton to the Asp233 residue, thus minimizing the chance of back proton transfer from hydronium to the NH2 group. The neutral NH2 group subsequently takes the proton from the O3' of A76 with a free energy barrier of 10.7 kcal/mol. In the next step, the deprotonated O3' makes a nucleophilic attack to the carbonyl carbon forming a tetrahedral transition state with a free energy barrier of 24.8 kcal/mol. Thus, the present work shows that the charging step proceeds through a multiple proton transfer mechanism where the amino group formed after deprotonation acts as the base to capture a proton from O3' of A76 rather than the phosphate group. The current study also shows the important role played by Asp233 in the proton transfer process.
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Affiliation(s)
- Saheb Dutta
- Department of Chemistry, Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Amalendu Chandra
- Department of Chemistry, Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
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17
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Zhang A, Zhuang X, Liu J, Huang J, Lin L, Tang Y, Zhao S, Li R, Wang B, Fang B, Hong W. Catalytic cycle of formate dehydrogenase captured by single-molecule conductance. Nat Catal 2023. [DOI: 10.1038/s41929-023-00928-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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18
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Nierzwicki Ł, Ahsan M, Palermo G. The Electronic Structure of Genome Editors from the First Principles. ELECTRONIC STRUCTURE (BRISTOL, ENGLAND) 2023; 5:014003. [PMID: 36926635 PMCID: PMC10016068 DOI: 10.1088/2516-1075/acb410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Genome editing based on the CRISPR-Cas9 system has paved new avenues for medicine, pharmaceutics, biotechnology, and beyond. This article reports the role of first-principles (ab-initio) molecular dynamics (MD) in the CRISPR-Cas9 revolution, achieving a profound understanding of the enzymatic function and offering valuable insights for enzyme engineering. We introduce the methodologies and explain the use of ab-initio MD simulations to characterize the two-metal dependent mechanism of DNA cleavage in the RuvC domain of the Cas9 enzyme, and how a second catalytic domain, HNH, cleaves the target DNA with the aid of a single metal ion. A detailed description of how ab-initio MD is combined with free-energy methods - i.e., thermodynamic integration and metadynamics - to break and form chemical bonds is given, explaining the use of these methods to determine the chemical landscape and establish the catalytic mechanism in CRISPR-Cas9. The critical role of classical methods is also discussed, explaining theory and application of constant pH MD simulations, used to accurately predict the catalytic residues' protonation states. Overall, first-principles methods are shown to unravel the electronic structure of the Cas9 enzyme, providing valuable insights that can serve for the design of genome editing tools with improved catalytic efficiency or controllable activity.
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Affiliation(s)
- Łukasz Nierzwicki
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Mohd Ahsan
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
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19
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Fang W, Feng S, Jiang Z, Liang W, Li P, Wang B. Understanding the Key Roles of pH Buffer in Accelerating Lignin Degradation by Lignin Peroxidase. JACS AU 2023; 3:536-549. [PMID: 36873691 PMCID: PMC9976348 DOI: 10.1021/jacsau.2c00649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
pH buffer plays versatile roles in both biology and chemistry. In this study, we unravel the critical role of pH buffer in accelerating degradation of the lignin substrate in lignin peroxidase (LiP) using QM/MM MD simulations and the nonadiabatic electron transfer (ET) and proton-coupled electron transfer (PCET) theories. As a key enzyme involved in lignin degradation, LiP accomplishes the oxidation of lignin via two consecutive ET reactions and the subsequent C-C cleavage of the lignin cation radical. The first one involves ET from Trp171 to the active species of Compound I, while the second one involves ET from the lignin substrate to the Trp171 radical. Differing from the common view that pH = 3 may enhance the oxidizing power of Cpd I via protonation of the protein environment, our study shows that the intrinsic electric fields have minor effects on the first ET step. Instead, our study shows that the pH buffer of tartaric acid plays key roles during the second ET step. Our study shows that the pH buffer of tartaric acid can form a strong H-bond with Glu250, which can prevent the proton transfer from the Trp171-H•+ cation radical to Glu250, thereby stabilizing the Trp171-H•+ cation radical for the lignin oxidation. In addition, the pH buffer of tartaric acid can enhance the oxidizing power of the Trp171-H•+ cation radical via both the protonation of the proximal Asp264 and the second-sphere H-bond with Glu250. Such synergistic effects of pH buffer facilitate the thermodynamics of the second ET step and reduce the overall barrier of lignin degradation by ∼4.3 kcal/mol, which corresponds to a rate acceleration of 103-fold that agrees with experiments. These findings not only expand our understanding on pH-dependent redox reactions in both biology and chemistry but also provide valuable insights into tryptophan-mediated biological ET reactions.
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Affiliation(s)
- Wenhan Fang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Shishi Feng
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Zhihui Jiang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Wanzhen Liang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
| | - Pengfei Li
- Department
of Chemistry and Biochemistry, Loyola University
Chicago, 1068 W. Sheridan Rd., Chicago, Illinois60660, United States
| | - Binju Wang
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering and Innovation Laboratory
for Sciences and Technologies of Energy Materials of Fujian Province
(IKKEM), Xiamen University, Xiamen361005, P. R. China
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20
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Waheed SO, Varghese A, DiCastri I, Kaski B, LaRouche C, Fields GB, Karabencheva-Christova TG. Mechanism of the Early Catalytic Events in the Collagenolysis by Matrix Metalloproteinase-1. Chemphyschem 2023; 24:e202200649. [PMID: 36161746 DOI: 10.1002/cphc.202200649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/23/2022] [Indexed: 02/04/2023]
Abstract
Metalloproteinase-1 (MMP-1) catalyzed collagen degradation is essential for a wide variety of normal physiological processes, while at the same time contributing to several diseases in humans. Therefore, a comprehensive understanding of this process is of great importance. Although crystallographic and spectroscopic studies provided fundamental information about the structure and function of MMP-1, the precise mechanism of collagen degradation especially considering the complex and flexible structure of the substrate, remains poorly understood. In addition, how the protein environment dynamically reorganizes at the atomic scale into a catalytically active state capable of collagen hydrolysis remains unknown. In this study, we applied experimentally-guided multiscale molecular modeling methods including classical molecular dynamics (MD), well-tempered (WT) classical metadynamics (MetD), combined quantum mechanics/molecular mechanics (QM/MM) MD and QM/MM MetD simulations to explore and characterize the early catalytic events of MMP-1 collagenolysis. Importantly the study provided a complete atomic and dynamic description of the transition from the open to the closed form of the MMP-1•THP complex. Notably, the formation of catalytically active Michaelis complex competent for collagen cleavage was characterized. The study identified the changes in the coordination state of the catalytic zinc(II) associated with the conformational transformation and the formation of catalytically productive ES complex. Our results confirm the essential role of the MMP-1 catalytic domain's α-helices (hA, hB and hC) and the linker region in the transition to the catalytically competent ES complex. Overall, the results provide unique mechanistic insight into the conformational transformations and associated changes in the coordination state of the catalytic zinc(II) that would be important for the design of effective MMP-1 inhibitors.
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Affiliation(s)
- Sodiq O Waheed
- Department of Chemistry, Michigan Technological University, Houghton, Michigan, 49931, USA
| | - Ann Varghese
- Department of Chemistry, Michigan Technological University, Houghton, Michigan, 49931, USA
| | - Isabella DiCastri
- Department of Chemistry, Michigan Technological University, Houghton, Michigan, 49931, USA
| | - Brenden Kaski
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, 49931, USA
| | - Ciara LaRouche
- Department of Chemical Engineering, Michigan Technological University, Houghton, Michigan, 49931, USA
| | - Gregg B Fields
- Department of Chemistry & Biochemistry and I-HEALTH, Florida Atlantic University, Jupiter, Florida, 33458, USA
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21
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Bylaska EJ, Tratnyek PG, Torralba-Sanchez TL, Edwards KC, Dixon DA, Pignatello JJ, Xu W. Computational Predictions of the Hydrolysis of 2,4,6-Trinitrotoluene (TNT) and 2,4-Dinitroanisole (DNAN). J Phys Chem A 2022; 126:9059-9075. [PMID: 36417759 DOI: 10.1021/acs.jpca.2c06014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Hydrolysis is a common transformation reaction that can affect the environmental fate of many organic compounds. In this study, three proposed mechanisms of alkaline hydrolysis of 2,4,6-trinitrotoluene (TNT) and 2,4-dinitroaniline (DNAN) were investigated with plane-wave density functional theory (DFT) combined with ab initio and classical molecular dynamics (AIMD/MM) free energy simulations, Gaussian basis set DFT calculations, and correlated molecular orbital theory calculations. Most of the computations in this study were carried out using the Arrows web-based tools. For each mechanism, Meisenheimer complex formation, nucleophilic aromatic substitution, and proton abstraction reaction energies and activation barriers were calculated for the reaction at each relevant site. For TNT, it was found that the most kinetically favorable first hydrolysis steps involve Meisenheimer complex formation by attachment of OH- at the C1 and C3 arene carbons and proton abstraction from the methyl group. The nucleophilic aromatic substitution reactions at the C2 and C4 arene carbons were found to be thermodynamically favorable. However, the calculated activation barriers were slightly lower than in previous studies, but still found to be ΔG‡ ≈ 18 kcal/mol using PBE0 AIMD/MM free energy simulations, suggesting that the reactions are not kinetically significant. For DNAN, the barriers of nucleophilic aromatic substitution were even greater (ΔG‡ > 29 kcal/mol PBE0 AIMD/MM). The most favorable hydrolysis reaction for DNAN was found to be a two-step process in which the hydroxyl first attacks the C1 carbon to form a Meisenheimer complex at the C1 arene carbon C1-(OCH3)OH-, and subsequently, the methoxy anion (-OCH3) at the C1 arene carbon dissociates and the proton shuttles from the C1-OH to the dissociated methoxy group, resulting in methanol and an aryloxy anion.
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Affiliation(s)
- Eric J Bylaska
- Fundamental Sciences, Pacific Northwest National Laboratory, Richland, Washington99354, United States
| | - Paul G Tratnyek
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, Oregon97239, United States
| | - Tifany L Torralba-Sanchez
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, Oregon97239, United States
| | - Kyle C Edwards
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama35487-0336, United States
| | - David A Dixon
- Department of Chemistry & Biochemistry, The University of Alabama, Tuscaloosa, Alabama35487-0336, United States
| | - Joseph J Pignatello
- Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, Connecticut06511, United States
| | - Wenqing Xu
- Civil and Environmental Engineering, Villanova University, Villanova, Pennsylvania19085, United States
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22
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Abstract
At the core of the CRISPR-Cas9 genome-editing technology, the endonuclease Cas9 introduces site-specific breaks in DNA. However, precise mechanistic information to ameliorating Cas9 function is still missing. Here, multi-microsecond molecular dynamics, free-energy and multiscale simulations are combined with solution NMR and DNA cleavage experiments to resolve the catalytic mechanism of target DNA cleavage. We show that the conformation of an active HNH nuclease is tightly dependent on the catalytic Mg2+, unveiling its cardinal structural role. This activated Mg2+-bound HNH is consistently described through molecular simulations, solution NMR and DNA cleavage assays, revealing also that the protonation state of the catalytic H840 is strongly affected by active site mutations. Finally, ab-initio QM(DFT)/MM simulations and metadynamics establish the catalytic mechanism, showing that the catalysis is activated by H840 and completed by K866, rationalising DNA cleavage experiments. This information is critical to enhance the enzymatic function of CRISPR-Cas9 toward improved genome-editing.
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23
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Affiliation(s)
- Vaishali Thakkur
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Chandan Kumar Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Nisanth N. Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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24
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Dutta S, Chandra A. Free Energy Landscape of the Adenylation Reaction of the Aminoacylation Process at the Active Site of Aspartyl tRNA Synthetase. J Phys Chem B 2022; 126:5821-5831. [PMID: 35895864 DOI: 10.1021/acs.jpcb.2c03843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The process of protein biosynthesis is initiated by the aminoacylation process where a transfer ribonucleic acid (tRNA) is charged by the attachment of its cognate amino acid at the active site of the corresponding aminoacyl tRNA synthetase enzyme. The first step of the aminoacylation process, known as the adenylation reaction, involves activation of the cognate amino acid where it reacts with a molecule of adenosine triphosphate (ATP) at the active site of the enzyme to form the aminoacyl adenylate and inorganic pyrophosphate. In the current work, we have investigated the adenylation reaction between aspartic acid and ATP at the active site of the fully solvated aspartyl tRNA synthetase (AspRS) from Escherichia coli in aqueous medium at room temperature through hybrid quantum mechanical/molecular mechanical (QM/MM) simulations combined with enhanced sampling methods of well-tempered and well-sliced metadynamics. The objective of the present work is to study the associated free energy landscape and reaction barrier and also to explore the effects of active site mutation on the free energy surface of the reaction. The current calculations include finite temperature effects on free energy profiles. In particular, apart from contributions of interaction energies, the current calculations also include contributions of conformational, vibrational, and translational entropy of active site residues, substrates, and also the rest of the solvated protein and surrounding water into the free energy calculations. The present QM/MM metadynamics simulations predict a free energy barrier of 23.35 and 23.5 kcal/mol for two different metadynamics methods used to perform the reaction at the active site of the wild type enzyme. The free energy barrier increases to 30.6 kcal/mol when Arg217, which is an important conserved residue of the wild type enzyme at its active site, is mutated by alanine. These free energy results including the effect of mutation compare reasonably well with those of kinetic experiments that are available in the literature. The current work also provides molecular details of structural changes of the reactants and surroundings as the system dynamically evolves along the reaction pathway from reactant to the product state through QM/MM metadynamics simulations.
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Affiliation(s)
- Saheb Dutta
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, India 208016
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, India 208016
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25
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Fu Y, Chen H, Fu W, Garcia-Borràs M, Yang Y, Liu P. Engineered P450 Atom-Transfer Radical Cyclases are Bifunctional Biocatalysts: Reaction Mechanism and Origin of Enantioselectivity. J Am Chem Soc 2022; 144:13344-13355. [PMID: 35830682 PMCID: PMC9339536 DOI: 10.1021/jacs.2c04937] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New-to-nature radical biocatalysis has recently emerged as a powerful strategy to tame fleeting open-shell intermediates for stereoselective transformations. In 2021, we introduced a novel metalloredox biocatalysis strategy that leverages the innate redox properties of the heme cofactor of P450 enzymes, furnishing new-to-nature atom-transfer radical cyclases (ATRCases) with excellent activity and stereoselectivity. Herein, we report a combined computational and experimental study to shed light on the mechanism and origins of enantioselectivity for this system. Molecular dynamics and quantum mechanics/molecular mechanics (QM/MM) calculations revealed an unexpected role of the key beneficial mutation I263Q. The glutamine residue serves as an essential hydrogen bond donor that engages with the carbonyl moiety of the substrate to promote bromine atom abstraction and enhance the enantioselectivity of radical cyclization. Therefore, the evolved ATRCase is a bifunctional biocatalyst, wherein the heme cofactor enables atom-transfer radical biocatalysis, while the hydrogen bond donor residue further enhances the activity and enantioselectivity. Unlike many enzymatic stereocontrol rationales based on a rigid substrate binding model, our computations demonstrate a high degree of rotational flexibility of the allyl moiety in an enzyme-substrate complex and succeeding intermediates. Therefore, the enantioselectivity is controlled by the radical cyclization transition states rather than the substrate orientation in ground-state complexes in the preceding steps. During radical cyclization, anchoring effects of the Q263 residue and steric interactions with the heme cofactor concurrently control the π-facial selectivity, allowing for highly enantioselective C-C bond formation. Our computational findings are corroborated by experiments with ATRCase mutants generated from site-directed mutagenesis.
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Affiliation(s)
- Yue Fu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Heyu Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Wenzhen Fu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Marc Garcia-Borràs
- Institut de Química Computacional i Catalisi (IQCC) and Departament de Química, Universitat de Girona, Girona 17003, Spain
| | - Yang Yang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Biomolecular Science and Engineering (BMSE) Program, University of California, Santa Barbara, California 93106, United States
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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26
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Cuxart I, Coines J, Esquivias O, Faijes M, Planas A, Biarnés X, Rovira C. Enzymatic Hydrolysis of Human Milk Oligosaccharides. The Molecular Mechanism of Bifidobacterium Bifidum Lacto- N-biosidase. ACS Catal 2022; 12:4737-4743. [PMID: 35465242 PMCID: PMC9016705 DOI: 10.1021/acscatal.2c00309] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/26/2022] [Indexed: 12/22/2022]
Abstract
![]()
Bifidobacterium
bifidum lacto-N-biosidase (LnbB)
is a critical enzyme for the degradation
of human milk oligosaccharides in the gut microbiota of breast-fed
infants. Guided by recent crystal structures, we unveil its molecular
mechanism of catalysis using QM/MM metadynamics. We show that the
oligosaccharide substrate follows 1S3/1,4B → [4E]‡ → 4C1/4H5 and 4C1/4H5 → [4E/4H5]‡ → 1,4B conformational itineraries for the two
successive reaction steps, with reaction free energy barriers in agreement
with experiments. The simulations also identify a critical histidine
(His263) that switches between two orientations to modulate the pKa of the acid/base residue, facilitating catalysis.
The reaction intermediate of LnbB is best depicted as an oxazolinium
ion, with a minor population of neutral oxazoline. The present study
sheds light on the processing of oligosaccharides of the early life
microbiota and will be useful for the engineering of LnbB and similar
glycosidases for biocatalysis.
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Affiliation(s)
- Irene Cuxart
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Joan Coines
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Oriol Esquivias
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Magda Faijes
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Xevi Biarnés
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08020 Barcelona, Spain
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27
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Pederson JP, McDaniel J. DFT-based QM/MM with Particle-Mesh Ewald for Direct, Long-Range Electrostatic Embedding. J Chem Phys 2022; 156:174105. [DOI: 10.1063/5.0087386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a DFT-based, QM/MM implementation with long-range electrostatic embedding achieved by direct real-space integration of the particle mesh Ewald (PME) computed electrostatic potential. The key transformation is the interpolation of the electrostatic potential from the PME grid to the DFT quadrature grid, from which integrals are easily evaluated utilizing standard DFT machinery. We provide benchmarks of the numerical accuracy with choice of grid size and real-space corrections, and demonstrate that good convergence is achieved while introducing nominal computational overhead. Furthermore, the approach requires only small modification to existing software packages, as is demonstrated with our implementation in the OpenMM and Psi4 software. After presenting convergence benchmarks, we evaluate the importance of long-range electrostatic embedding in three solute/solvent systems modeled with QM/MM. Water and BMIM/BF4 ionic liquid were considered as ``simple' and ``complex' solvents respectively, with water and p-phenylenediamine (PPD) solute molecules treated at QM level of theory. While electrostatic embedding with standard real-space truncation may introduce negligible error for simple systems such as water solute in water solvent, errors become more significant when QM/MM is applied to complex solvents such as ionic liquids. An extreme example is the electrostatic embedding energy for oxidized PPD in BMIM/BF4 for which real-space truncation produces severe error even at 2-3 nm cutoff distances. This latter example illustrates that utilization of QM/MM to compute redox potentials within concentrated electrolytes/ionic media requires carefully chosen long-range electrostatic embedding algorithms, with our presented algorithm providing a general and robust approach.
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Affiliation(s)
| | - Jesse McDaniel
- Chemistry, Georgia Institute of Technology, United States of America
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28
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Mouvet F, Villard J, Bolnykh V, Rothlisberger U. Recent Advances in First-Principles Based Molecular Dynamics. Acc Chem Res 2022; 55:221-230. [PMID: 35026115 DOI: 10.1021/acs.accounts.1c00503] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
First-principles molecular dynamics (FPMD) and its quantum mechanical-molecular mechanical (QM/MM) extensions are powerful tools to follow the real-time dynamics of a broad variety of systems in their ground as well as electronically excited states. The continued advances in computational power have enabled simulations of QM regions of larger sizes for more extended time scales. In addition, development of the parallel algorithms has boosted the performance of QM/MM methods even on existing computer architectures. In the case of density functional-based FPMD, systems of several hundreds to thousands of atoms can now be customarily simulated for tens to hundreds of picoseconds. In spite of this progress, the time scale limitations remain severe, especially when high-rung exchange-correlation functionals or high-level wave function based quantum mechanical methods are used. To ameliorate this, a large number of enhanced sampling methods have been introduced but most of the approaches that have been developed to increase the efficiency of FPMD based simulations sacrifice the real-time dynamics in favor of enhancing sampling. Here, we present some recent advances in boosting the efficiency of FPMD based simulations while keeping the full dynamic information. These include a highly efficient recent implementation of FPMD-based QM/MM simulations that not only enables fully flexible combinations of different electronic structure methods and force fields via a highly efficient communication library, it also fully exploits parallelism for both quantum and classical descriptions. The second type of acceleration methods we discuss is a large family of specially devised multiple-time-step algorithms that make use of suitable breakups of the total nuclear forces into fast components that can be calculated via lower level methods and slowly varying correction forces evaluated with a high-level method at long time intervals. The computational gain of this scheme mostly depends on the cost difference between the two methods and advantageous combinations can yield large speedups without compromising the accuracy of the high-level method. And finally, the third class of FPMD acceleration methods presented here are machine learning models to accelerated FPMD and their powerful combinations with multiple-time-step techniques. The combination of all the approaches enables substantial speedups of FPMD simulations of several orders of magnitude while fully preserving the real-time dynamics and accuracy.
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Affiliation(s)
- François Mouvet
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Justin Villard
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Viacheslav Bolnykh
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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29
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Salehi SM, Käser S, Töpfer K, Diamantis P, Pfister R, Hamm P, Rothlisberger U, Meuwly M. Hydration dynamics and IR spectroscopy of 4-fluorophenol. Phys Chem Chem Phys 2022; 24:26046-26060. [PMID: 36268728 PMCID: PMC9627945 DOI: 10.1039/d2cp02857c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Halogenated groups are relevant in pharmaceutical applications and potentially useful spectroscopic probes for infrared spectroscopy. In this work, the structural dynamics and infrared spectroscopy of para-fluorophenol (F-PhOH) and phenol (PhOH) is investigated in the gas phase and in water using a combination of experiment and molecular dynamics (MD) simulations. The gas phase and solvent dynamics around F-PhOH and PhOH is characterized from atomistic simulations using empirical energy functions with point charges or multipoles for the electrostatics, Machine Learning (ML) based parametrizations and with full ab initio (QM) and mixed Quantum Mechanical/Molecular Mechanics (QM/MM) simulations with a particular focus on the CF- and OH-stretch region. The CF-stretch band is heavily mixed with other modes whereas the OH-stretch in solution displays a characteristic high-frequency peak around 3600 cm−1 most likely associated with the –OH group of PhOH and F-PhOH together with a characteristic progression below 3000 cm−1 due to coupling with water modes which is also reproduced by several of the simulations. Solvent and radial distribution functions indicate that the CF-site is largely hydrophobic except for simulations using point charges which renders them unsuited for correctly describing hydration and dynamics around fluorinated sites. The hydrophobic character of the CF-group is particularly relevant for applications in pharmaceutical chemistry with a focus on local hydration and interaction with the surrounding protein. Halogenated groups are relevant in pharmaceutical applications and potentially useful spectroscopic probes for infrared spectroscopy.![]()
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Affiliation(s)
- Seyedeh Maryam Salehi
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Silvan Käser
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Kai Töpfer
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Polydefkis Diamantis
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Rolf Pfister
- Department of Chemistry, University of Zurich, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
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30
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Piccini G, Lee MS, Yuk SF, Zhang D, Collinge G, Kollias L, Nguyen MT, Glezakou VA, Rousseau R. Ab initio molecular dynamics with enhanced sampling in heterogeneous catalysis. Catal Sci Technol 2022. [DOI: 10.1039/d1cy01329g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enhanced sampling ab initio simulations enable to study chemical phenomena in catalytic systems including thermal effects & anharmonicity, & collective dynamics describing enthalpic & entropic contributions, which can significantly impact on reaction free energy landscapes.
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Affiliation(s)
- GiovanniMaria Piccini
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
- Istituto Eulero, Università della Svizzera italiana, Via Giuseppe Buffi 13, Lugano, Ticino, Switzerland
| | - Mal-Soon Lee
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Simuck F. Yuk
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Difan Zhang
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Greg Collinge
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Loukas Kollias
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Manh-Thuong Nguyen
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Vassiliki-Alexandra Glezakou
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Roger Rousseau
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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31
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Reinholdt P, Kongsted J, Lipparini F. Fast Approximate but Accurate QM/MM Interactions for Polarizable Embedding. J Chem Theory Comput 2021; 18:344-356. [PMID: 34951300 DOI: 10.1021/acs.jctc.1c01037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The coupling between the quantum (QM) and classical (MM) regions is often one of the computational bottlenecks when applying polarizable QM/MM to computational spectroscopy. In this Article, we explore three strategies to approximate the QM/MM coupling based on multipole expansion techniques. The implementations of these approximations are benchmarked in terms of both accuracy and computational efficiency and are furthermore applied to the calculation of spectroscopic properties including both one- and two-photon absorption strengths. We show that the proposed strategies provide significant computational savings without compromising the accuracy of the calculated spectroscopic properties.
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Affiliation(s)
- Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, 56127 Pisa, Italy
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32
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Kirsch T, Olsen JMH, Bolnykh V, Meloni S, Ippoliti E, Rothlisberger U, Cascella M, Gauss J. Wavefunction-Based Electrostatic-Embedding QM/MM Using CFOUR through MiMiC. J Chem Theory Comput 2021; 18:13-24. [PMID: 34905353 DOI: 10.1021/acs.jctc.1c00878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present an interface of the wavefunction-based quantum chemical software CFOUR to the multiscale modeling framework MiMiC. Electrostatic embedding of the quantum mechanical (QM) part is achieved by analytic evaluation of one-electron integrals in CFOUR, while the rest of the QM/molecular mechanical (MM) operations are treated according to the previous MiMiC-based QM/MM implementation. Long-range electrostatic interactions are treated by a multipole expansion of the potential from the QM electron density to reduce the computational cost without loss of accuracy. Testing on model water/water systems, we verified that the CFOUR interface to MiMiC is robust, guaranteeing fast convergence of the self-consistent field cycles and optimal conservation of the energy during the integration of the equations of motion. Finally, we verified that the CFOUR interface to MiMiC is compatible with the use of a QM/QM multiple time-step algorithm, which effectively reduces the cost of ab initio MD (AIMD) or QM/MM-MD simulations using higher level wavefunction-based approaches compared to cheaper density functional theory-based ones. The new wavefunction-based AIMD and QM/MM-MD implementations were tested and validated for a large number of wavefunction approaches, including Hartree-Fock and post-Hartree-Fock methods like Møller-Plesset, coupled-cluster, and complete active space self-consistent field.
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Affiliation(s)
- Till Kirsch
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | | | - Viacheslav Bolnykh
- Institute for Advanced Simulation (IAS-5) and Institute of Neuroscience and Medicine (INM-9), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Simone Meloni
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Universita degli Studi di Ferrara, 44121 Ferrara, Italy
| | - Emiliano Ippoliti
- Institute for Advanced Simulation (IAS-5) and Institute of Neuroscience and Medicine (INM-9), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Michele Cascella
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
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33
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Soniya K, Chandra A. Free Energy Landscape and Proton Transfer Pathways of the Transimination Reaction at the Active site of the Serine Hydroxymethyltransferase Enzyme in Aqueous Medium. J Phys Chem B 2021; 125:11848-11856. [PMID: 34696588 DOI: 10.1021/acs.jpcb.1c05864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Serine hydroxymethyltransferase (SHMT) is a ubiquitous enzyme belonging to the fold type I or aspartate aminotransferase (AspAT) family of the pyridoxal 5'-phosphate (PLP)-dependent enzymes. Like other PLP-dependent enzymes, SHMT also undergoes the so-called transimination reaction before exhibiting its enzymatic activity. The transimination process constitutes an important pre-step for all PLP-dependent enzymes, where an internal aldimine of the PLP-enzyme complex gets converted to an external aldimine of the substrate-PLP complex at the active site of the enzyme. In case of the transimination reaction involving SHMT, the PLP molecule bound to the active site lysine residue of SHMT (internal aldimine) gets detached from the enzyme by a serine substrate to produce an external aldimine complex, where the PLP is now bound to the serine substrate. In the current study, the free energy surfaces and reaction pathways of different steps of the transimination reaction at the active site of SHMT are investigated by employing hybrid quantum mechanical/molecular mechanical (QM/MM) simulations combined with metadynamics methods of rare event sampling. It is found that the process of transimination involving serine and PLP at the active site of the SHMT enzyme takes place through different elementary steps such as the formation of the first geminal diamine intermediate (GDI1), transfer of a proton from the substrate serine to the phenolic oxygen of PLP, followed by another proton transfer from PLP to the amine nitrogen of lysine with the formation of the second geminal diamine intermediate (GDI2), and finally, detachment of the active site lysine residue from PLP to produce the external aldimine.
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Affiliation(s)
- Kumari Soniya
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
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34
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Šmak P, Tvaroška I, Koča J. The catalytic reaction mechanism of tyrosylprotein sulfotransferase-1. Phys Chem Chem Phys 2021; 23:23850-23860. [PMID: 34647946 DOI: 10.1039/d1cp03718h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tyrosine sulfation alters the biological activity of many proteins involved in different physiological and pathophysiological conditions, such as non-specific immune reaction, response to inflammation and ischemia, targeting of leukocytes and stem cells, or the formation of cancer metastases. Tyrosine sulfation is catalyzed by the enzymes tyrosylprotein sulfotransferases (TPST). In this study, we used QM/MM Car-Parrinello metadynamics simulations together with QM/MM potential energy calculations to investigate the catalytic mechanism of isoform TPST-1. The structural changes along the reaction coordinate are analyzed and discussed. Furthermore, both the methods supported the SN2 type of catalytic mechanism. The reaction barrier obtained from CPMD metadynamics was 12.8 kcal mol-1, and the potential energy scan led to reaction barriers of 11.6 kcal mol-1 and 13.7 kcal mol-1 with the B3LYP and OPBE functional, respectively. The comparison of the two methods (metadynamics and potential energy scan) may be helpful for future mechanistic studies. The insight into the reaction mechanism of TPST-1 might help with the rational design of transition-state TPST inhibitors.
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Affiliation(s)
- Pavel Šmak
- National Center for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Igor Tvaroška
- National Center for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic.,Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovak Republic.
| | - Jaroslav Koča
- National Center for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic.,Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
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35
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Piniello B, Lira-Navarrete E, Takeuchi H, Takeuchi M, Haltiwanger RS, Hurtado-Guerrero R, Rovira C. Asparagine Tautomerization in Glycosyltransferase Catalysis. The Molecular Mechanism of Protein O-Fucosyltransferase 1. ACS Catal 2021; 11:9926-9932. [PMID: 34868727 PMCID: PMC8631701 DOI: 10.1021/acscatal.1c01785] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/19/2021] [Indexed: 12/12/2022]
Abstract
![]()
O-glycosylation is a post-translational protein
modification essential to life. One of the enzymes involved in this
process is protein O-fucosyltransferase 1 (POFUT1),
which fucosylates threonine or serine residues within a specific sequence
context of epidermal growth factor-like domains (EGF-LD). Unlike most
inverting glycosyltransferases, POFUT1 lacks a basic residue in the
active site that could act as a catalytic base to deprotonate the
Thr/Ser residue of the EGF-LD acceptor during the chemical reaction.
Using quantum mechanics/molecular mechanics (QM/MM) methods on recent
crystal structures, as well as mutagenesis experiments, we uncover
the enzyme catalytic mechanism, revealing that it involves proton
shuttling through an active site asparagine, conserved among species,
which undergoes tautomerization. This mechanism is consistent with
experimental kinetic analysis of Caenorhabditis elegans POFUT1 Asn43 mutants, which ablate enzyme activity even if mutated
to Asp, the canonical catalytic base in inverting glycosyltransferases.
These results will aid inhibitor development for Notch-associated O-glycosylation disorders.
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Affiliation(s)
- Beatriz Piniello
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Erandi Lira-Navarrete
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, 50018 Zaragoza, Spain
| | - Hideyuki Takeuchi
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, The University of Georgia, Athens, Georgia 30602, United States
| | - Megumi Takeuchi
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, The University of Georgia, Athens, Georgia 30602, United States
| | - Robert S. Haltiwanger
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, The University of Georgia, Athens, Georgia 30602, United States
| | - Ramón Hurtado-Guerrero
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, 50018 Zaragoza, Spain
- Fundación ARAID, 50018 Zaragoza, Spain
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, 1017 Copenhagen, Denmark
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
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Pieri E, Lahana D, Chang AM, Aldaz CR, Thompson KC, Martínez TJ. The non-adiabatic nanoreactor: towards the automated discovery of photochemistry. Chem Sci 2021; 12:7294-7307. [PMID: 34163820 PMCID: PMC8171323 DOI: 10.1039/d1sc00775k] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The ab initio nanoreactor has previously been introduced to automate reaction discovery for ground state chemistry. In this work, we present the nonadiabatic nanoreactor, an analogous framework for excited state reaction discovery. We automate the study of nonadiabatic decay mechanisms of molecules by probing the intersection seam between adiabatic electronic states with hyper-real metadynamics, sampling the branching plane for relevant conical intersections, and performing seam-constrained path searches. We illustrate the effectiveness of the nonadiabatic nanoreactor by applying it to benzene, a molecule with rich photochemistry and a wide array of photochemical products. Our study confirms the existence of several types of S0/S1 and S1/S2 conical intersections which mediate access to a variety of ground state stationary points. We elucidate the connections between conical intersection energy/topography and the resulting photoproduct distribution, which changes smoothly along seam space segments. The exploration is performed with minimal user input, and the protocol requires no previous knowledge of the photochemical behavior of a target molecule. We demonstrate that the nonadiabatic nanoreactor is a valuable tool for the automated exploration of photochemical reactions and their mechanisms.
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Affiliation(s)
- Elisa Pieri
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
| | - Dean Lahana
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
| | - Alexander M Chang
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
| | - Cody R Aldaz
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
| | - Keiran C Thompson
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
| | - Todd J Martínez
- Department of Chemistry, The PULSE Institute, Stanford University Stanford CA 94305 USA .,SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA
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37
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Mandal S, Thakkur V, Nair NN. Achieving an Order of Magnitude Speedup in Hybrid-Functional- and Plane-Wave-Based Ab Initio Molecular Dynamics: Applications to Proton-Transfer Reactions in Enzymes and in Solution. J Chem Theory Comput 2021; 17:2244-2255. [PMID: 33740375 DOI: 10.1021/acs.jctc.1c00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio molecular dynamics (MD) with hybrid density functionals and a plane wave basis is computationally expensive due to the high computational cost of exact exchange energy evaluation. Recently, we proposed a strategy to combine adaptively compressed exchange (ACE) operator formulation and a multiple time step integration scheme to reduce the computational cost significantly [J. Chem. Phys. 2019, 151, 151102 ]. However, it was found that the construction of the ACE operator, which has to be done at least once in every MD time step, is computationally expensive. In the present work, systematic improvements are introduced to further speed up by employing localized orbitals for the construction of the ACE operator. By this, we could achieve a computational speedup of an order of magnitude for a periodic system containing 32 water molecules. Benchmark calculations were carried out to show the accuracy and efficiency of the method in predicting the structural and dynamical properties of bulk water. To demonstrate the applicability, computationally intensive free-energy computations at the level of hybrid density functional theory were performed to investigate (a) methyl formate hydrolysis reaction in neutral aqueous media and (b) proton-transfer reaction within the active-site residues of the class C β-lactamase enzyme.
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Affiliation(s)
- Sagarmoy Mandal
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India.,Interdisciplinary Center for Molecular Materials and Computer Chemistry Center, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstr. 25, Erlangen 91052, Germany
| | - Vaishali Thakkur
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur (IITK), Kanpur 208016, India
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38
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Protonation Equilibrium in the Active Site of the Photoactive Yellow Protein. Molecules 2021; 26:molecules26072025. [PMID: 33918211 PMCID: PMC8037372 DOI: 10.3390/molecules26072025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/30/2021] [Accepted: 03/30/2021] [Indexed: 11/17/2022] Open
Abstract
The role and existence of low-barrier hydrogen bonds (LBHBs) in enzymatic and protein activity has been largely debated. An interesting case is that of the photoactive yellow protein (PYP). In this protein, two short HBs adjacent to the chromophore, p-coumaric acid (pCA), have been identified by X-ray and neutron diffraction experiments. However, there is a lack of agreement on the chemical nature of these H-bond interactions. Additionally, no consensus has been reached on the presence of LBHBs in the active site of the protein, despite various experimental and theoretical studies having been carried out to investigate this issue. In this work, we perform a computational study that combines classical and density functional theory (DFT)-based quantum mechanical/molecular mechanical (QM/MM) simulations to shed light onto this controversy. Furthermore, we aim to deepen our understanding of the chemical nature and dynamics of the protons involved in the two short hydrogen bonds that, in the dark state of PYP, connect pCA with the two binding pocket residues (E46 and Y42). Our results support the existence of a strong LBHB between pCA and E46, with the H fully delocalized and shared between both the carboxylic oxygen of E46 and the phenolic oxygen of pCA. Additionally, our findings suggest that the pCA interaction with Y42 can be suitably described as a typical short ionic H-bond of moderate strength that is fully localized on the phenolic oxygen of Y42.
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Peng W, Qu X, Shaik S, Wang B. Deciphering the oxygen activation mechanism at the CuC site of particulate methane monooxygenase. Nat Catal 2021. [DOI: 10.1038/s41929-021-00591-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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40
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Morawietz T, Artrith N. Machine learning-accelerated quantum mechanics-based atomistic simulations for industrial applications. J Comput Aided Mol Des 2021; 35:557-586. [PMID: 33034008 PMCID: PMC8018928 DOI: 10.1007/s10822-020-00346-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/26/2020] [Indexed: 01/13/2023]
Abstract
Atomistic simulations have become an invaluable tool for industrial applications ranging from the optimization of protein-ligand interactions for drug discovery to the design of new materials for energy applications. Here we review recent advances in the use of machine learning (ML) methods for accelerated simulations based on a quantum mechanical (QM) description of the system. We show how recent progress in ML methods has dramatically extended the applicability range of conventional QM-based simulations, allowing to calculate industrially relevant properties with enhanced accuracy, at reduced computational cost, and for length and time scales that would have otherwise not been accessible. We illustrate the benefits of ML-accelerated atomistic simulations for industrial R&D processes by showcasing relevant applications from two very different areas, drug discovery (pharmaceuticals) and energy materials. Writing from the perspective of both a molecular and a materials modeling scientist, this review aims to provide a unified picture of the impact of ML-accelerated atomistic simulations on the pharmaceutical, chemical, and materials industries and gives an outlook on the exciting opportunities that could emerge in the future.
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Affiliation(s)
- Tobias Morawietz
- Bayer AG, Pharmaceuticals, R&D, Digital Technologies, Computational Molecular Design, 42096 Wuppertal, Germany
| | - Nongnuch Artrith
- Department of Chemical Engineering, Columbia University, New York, NY 10027 USA
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41
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Cantu DC. Predicting lanthanide coordination structures in solution with molecular simulation. Methods Enzymol 2021; 651:193-233. [PMID: 33888204 DOI: 10.1016/bs.mie.2021.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The chemical and physical properties of lanthanide coordination complexes can significantly change with small variations in their molecular structure. Further, in solution, coordination structures (e.g., lanthanide-ligand complexes) are dynamic. Resolving solution structures, computationally or experimentally, is challenging because structures in solution have limited spatial restrictions and are responsive to chemical or physical changes in their surroundings. To determine structures of lanthanide-ligand complexes in solution, a molecular simulation approach is presented in this chapter, which concurrently considers chemical reactions and molecular dynamics. Lanthanide ion, ligand, solvent, and anion molecules are explicitly included to identify, in atomic resolution, lanthanide coordination structures in solution. The computational protocol described is applicable to determining the molecular structure of lanthanide-ligand complexes, particularly with ligands known to bind lanthanides but whose structures have not been resolved, as well as with ligands not previously known to bind lanthanide ions. The approach in this chapter is also relevant to elucidating lanthanide coordination in more intricate structures, such as in the active site of enzymes.
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Affiliation(s)
- David C Cantu
- Department of Chemical and Materials Engineering, University of Nevada, Reno, Reno, NV, United States.
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42
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Pan X, Nam K, Epifanovsky E, Simmonett AC, Rosta E, Shao Y. A simplified charge projection scheme for long-range electrostatics in ab initio QM/MM calculations. J Chem Phys 2021; 154:024115. [PMID: 33445891 DOI: 10.1063/5.0038120] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In a previous work [Pan et al., Molecules 23, 2500 (2018)], a charge projection scheme was reported, where outer molecular mechanical (MM) charges [>10 Å from the quantum mechanical (QM) region] were projected onto the electrostatic potential (ESP) grid of the QM region to accurately and efficiently capture long-range electrostatics in ab initio QM/MM calculations. Here, a further simplification to the model is proposed, where the outer MM charges are projected onto inner MM atom positions (instead of ESP grid positions). This enables a representation of the long-range MM electrostatic potential via augmentary charges (AC) on inner MM atoms. Combined with the long-range electrostatic correction function from Cisneros et al. [J. Chem. Phys. 143, 044103 (2015)] to smoothly switch between inner and outer MM regions, this new QM/MM-AC electrostatic model yields accurate and continuous ab initio QM/MM electrostatic energies with a 10 Å cutoff between inner and outer MM regions. This model enables efficient QM/MM cluster calculations with a large number of MM atoms as well as QM/MM calculations with periodic boundary conditions.
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Affiliation(s)
- Xiaoliang Pan
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Pkwy, Norman, Oklahoma 73019, USA
| | - Kwangho Nam
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, USA
| | - Evgeny Epifanovsky
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Andrew C Simmonett
- National Institutes of Health-National Heart, Lung and Blood Institute, Laboratory of Computational Biology, Bethesda, Maryland 20892, USA
| | - Edina Rosta
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Pkwy, Norman, Oklahoma 73019, USA
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43
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Morais MAB, Coines J, Domingues MN, Pirolla RAS, Tonoli CCC, Santos CR, Correa JBL, Gozzo FC, Rovira C, Murakami MT. Two distinct catalytic pathways for GH43 xylanolytic enzymes unveiled by X-ray and QM/MM simulations. Nat Commun 2021; 12:367. [PMID: 33446650 PMCID: PMC7809346 DOI: 10.1038/s41467-020-20620-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023] Open
Abstract
Xylanolytic enzymes from glycoside hydrolase family 43 (GH43) are involved in the breakdown of hemicellulose, the second most abundant carbohydrate in plants. Here, we kinetically and mechanistically describe the non-reducing-end xylose-releasing exo-oligoxylanase activity and report the crystal structure of a native GH43 Michaelis complex with its substrate prior to hydrolysis. Two distinct calcium-stabilized conformations of the active site xylosyl unit are found, suggesting two alternative catalytic routes. These results are confirmed by QM/MM simulations that unveil the complete hydrolysis mechanism and identify two possible reaction pathways, involving different transition state conformations for the cleavage of xylooligosaccharides. Such catalytic conformational promiscuity in glycosidases is related to the open architecture of the active site and thus might be extended to other exo-acting enzymes. These findings expand the current general model of catalytic mechanism of glycosidases, a main reaction in nature, and impact on our understanding about their interaction with substrates and inhibitors.
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Affiliation(s)
- Mariana A B Morais
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
- Departament de Química Inorgànica i Orgànica & Institut de Química Teórica i Computacional (IQTCUB), Universitat de Barcelona, Barcelona, 08028, Spain
| | - Joan Coines
- Departament de Química Inorgànica i Orgànica & Institut de Química Teórica i Computacional (IQTCUB), Universitat de Barcelona, Barcelona, 08028, Spain
| | - Mariane N Domingues
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
| | - Renan A S Pirolla
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
| | - Celisa C C Tonoli
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
| | - Camila R Santos
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
| | - Jessica B L Correa
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil
| | - Fabio C Gozzo
- Dalton Mass Spectrometry Laboratory, Institute of Chemistry, University of Campinas, Campinas, 13083-970, Brazil
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & Institut de Química Teórica i Computacional (IQTCUB), Universitat de Barcelona, Barcelona, 08028, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08010, Spain.
| | - Mario T Murakami
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, 13083-100, Brazil.
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44
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Dutta Banik S, Bankura A, Chandra A. A QM/MM simulation study of transamination reaction at the active site of aspartate aminotransferase: Free energy landscape and proton transfer pathways. J Comput Chem 2020; 41:2684-2694. [PMID: 32932551 DOI: 10.1002/jcc.26422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/08/2020] [Accepted: 09/03/2020] [Indexed: 11/10/2022]
Abstract
Transaminase is a key enzyme for amino acid metabolism, which reversibly catalyzes the transamination reaction with the help of PLP (pyridoxal 5' -phosphate) as its cofactor. Here we have investigated the mechanism and free energy landscape of the transamination reaction involving the aspartate transaminase (AspTase) enzyme and aspartate-PLP (Asp-PLP) complex using QM/MM simulation and metadynamics methods. The reaction is found to follow a stepwise mechanism where the active site residue Lys258 acts as a base to shuttle a proton from α-carbon (CA) to imine carbon (C4A) of the PLP-Asp Schiff base. In the first step, the Lys258 abstracts the CA proton of the substrate leading to the formation of a carbanionic intermediate which is followed by the reprotonation of the Asp-PLP Schiff base at C4A atom by Lys258. It is found that the free energy barrier for the proton abstraction by Lys258 and that for the reprotonation are 17.85 and 3.57 kcal/mol, respectively. The carbanionic intermediate is 7.14 kcal/mol higher in energy than the reactant. Hence, the first step acts as the rate limiting step. The present calculations also show that the Lys258 residue undergoes a conformational change after the first step of transamination reaction and becomes proximal to C4A atom of the Asp-PLP Schiff base to favor the second step. The active site residues Tyr70* and Gly38 anchor the Lys258 in proper position and orientation during the first step of the reaction and stabilize the positive charge over Lys258 generated at the intermediate step.
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Affiliation(s)
- Sindrila Dutta Banik
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
| | - Arindam Bankura
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India
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45
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Palermo G, Spinello A, Saha A, Magistrato A. Frontiers of metal-coordinating drug design. Expert Opin Drug Discov 2020; 16:497-511. [PMID: 33874825 DOI: 10.1080/17460441.2021.1851188] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: The occurrence of metal ions in biomolecules is required to exert vital cellular functions. Metal-containing biomolecules can be modulated by small-molecule inhibitors targeting their metal-moiety. As well, the discovery of cisplatin ushered the rational discovery of metal-containing-drugs. The use of both drug types exploiting metal-ligand interactions is well established to treat distinct pathologies. Therefore, characterizing and leveraging metal-coordinating drugs is a pivotal, yet challenging, part of medicinal chemistry.Area covered: Atomic-level simulations are increasingly employed to overcome the challenges met by traditional drug-discovery approaches and to complement wet-lab experiments in elucidating the mechanisms of drugs' action. Multiscale simulations, allow deciphering the mechanism of metal-binding inhibitors and metallo-containing-drugs, enabling a reliable description of metal-complexes in their biological environment. In this compendium, the authors review selected applications exploiting the metal-ligand interactions by focusing on understanding the mechanism and design of (i) inhibitors targeting iron and zinc-enzymes, and (ii) ruthenium and gold-based anticancer agents targeting the nucleosome and aquaporin protein, respectively.Expert opinion: The showcased applications exemplify the current role and the potential of atomic-level simulations and reveal how their synergic use with experiments can contribute to uncover fundamental mechanistic facets and exploit metal-ligand interactions in medicinal chemistry.
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Affiliation(s)
- Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California Riverside, Riverside, United States
| | - Angelo Spinello
- National Research Council (CNR) of Italy, Institute of Material (IOM) @ International School for Advanced Studies (SISSA), Trieste, Italy
| | - Aakash Saha
- Department of Bioengineering, University of California Riverside, Riverside, United States
| | - Alessandra Magistrato
- National Research Council (CNR) of Italy, Institute of Material (IOM) @ International School for Advanced Studies (SISSA), Trieste, Italy
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46
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Cheng HP, Deumens E, Freericks JK, Li C, Sanders BA. Application of Quantum Computing to Biochemical Systems: A Look to the Future. Front Chem 2020; 8:587143. [PMID: 33330375 PMCID: PMC7732423 DOI: 10.3389/fchem.2020.587143] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022] Open
Abstract
Chemistry is considered as one of the more promising applications to science of near-term quantum computing. Recent work in transitioning classical algorithms to a quantum computer has led to great strides in improving quantum algorithms and illustrating their quantum advantage. Because of the limitations of near-term quantum computers, the most effective strategies split the work over classical and quantum computers. There is a proven set of methods in computational chemistry and materials physics that has used this same idea of splitting a complex physical system into parts that are treated at different levels of theory to obtain solutions for the complete physical system for which a brute force solution with a single method is not feasible. These methods are variously known as embedding, multi-scale, and fragment techniques and methods. We review these methods and then propose the embedding approach as a method for describing complex biochemical systems, with the parts not only treated with different levels of theory, but computed with hybrid classical and quantum algorithms. Such strategies are critical if one wants to expand the focus to biochemical molecules that contain active regions that cannot be properly explained with traditional algorithms on classical computers. While we do not solve this problem here, we provide an overview of where the field is going to enable such problems to be tackled in the future.
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Affiliation(s)
- Hai-Ping Cheng
- Quantum Theory Project, Department of Physics, University of Florida, Gainesville, FL, United States
| | - Erik Deumens
- Quantum Theory Project, Department of Physics, University of Florida, Gainesville, FL, United States
| | - James K. Freericks
- Department of Physics, Georgetown University, Washington, DC, United States
| | - Chenglong Li
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, United States
| | - Beverly A. Sanders
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL, United States
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47
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Casalino L, Nierzwicki Ł, Jinek M, Palermo G. Catalytic Mechanism of Non-Target DNA Cleavage in CRISPR-Cas9 Revealed by Ab Initio Molecular Dynamics. ACS Catal 2020; 10:13596-13605. [PMID: 33520346 PMCID: PMC7842700 DOI: 10.1021/acscatal.0c03566] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
CRISPR-Cas9 is a cutting-edge genome editing technology, which uses the endonuclease Cas9 to introduce mutations at desired sites of the genome. This revolutionary tool is promising to treat a myriad of human genetic diseases. Nevertheless, the molecular basis of DNA cleavage, which is a fundamental step for genome editing, has not been established. Here, quantum-classical molecular dynamics (MD) and free energy methods are used to disclose the two-metal-dependent mechanism of phosphodiester bond cleavage in CRISPR-Cas9. Ab initio MD reveals a conformational rearrangement of the Mg2+-bound RuvC active site, which entails the relocation of H983 to act as a general base. Then, the DNA cleavage proceeds through a concerted associative pathway fundamentally assisted by the joint dynamics of the two Mg2+ ions. This clarifies previous controversial experimental evidence, which could not fully establish the catalytic role of the conserved H983 and the metal cluster conformation. The comparison with other two-metal-dependent enzymes supports the identified mechanism and suggests a common catalytic strategy for genome editing and recombination. Overall, the non-target DNA cleavage catalysis described here resolves a fundamental open question in the CRISPR-Cas9 biology and provides valuable insights for improving the catalytic efficiency and the metal-dependent function of the Cas9 enzyme, which are at the basis of the development of genome editing tools.
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Affiliation(s)
- Lorenzo Casalino
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Łukasz Nierzwicki
- Department of Bioengineering, University of California Riverside, Riverside, California 92521, United States
| | - Martin Jinek
- Department of Biochemistry, University of Zürich, CH-8057 Zürich, Switzerland
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
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48
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Diamantis P, Tavernelli I, Rothlisberger U. Redox Properties of Native and Damaged DNA from Mixed Quantum Mechanical/Molecular Mechanics Molecular Dynamics Simulations. J Chem Theory Comput 2020; 16:6690-6701. [PMID: 32926773 DOI: 10.1021/acs.jctc.0c00568] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The redox properties of two large DNA fragments composed of 39 base pairs, differing only by an 8-oxoguanine (8oxoG) defect replacing a guanine (G), were investigated in physiological conditions using mixed quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulations. The quantum region of the native fragment comprised 3 G-C base pairs, while one G was replaced by an 8oxoG in the defect fragment. The calculated values for the redox free energy are 6.55 ± 0.28 eV and 5.62 ± 0.30 eV for the native and the 8oxoG-containing fragment, respectively. The respective estimates for the reorganization free energy are 1.25 ± 0.18 eV and 1.00 ± 0.18 eV. Both reactions follow the Marcus theory for electron transfer. The large difference in redox potential between the two fragments shows that replacement of a G by an 8oxoG renders the DNA more easily oxidizable. This finding is in agreement with the suggestion that DNA fragments containing an 8oxoG defect can act as sinks of oxidative damage that protect the rest of the genome from assault. In addition, the difference in redox potential between the native and the defect DNA fragment indicates that a charge transfer-based mechanism for the recognition of DNA defects might be feasible, in line with recent suggestions based on experimental observations.
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Affiliation(s)
- Polydefkis Diamantis
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
| | - Ivano Tavernelli
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
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49
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Patil PR, Vithani N, Singh V, Kumar A, Prakash B. A revised mechanism for (p)ppGpp synthesis by Rel proteins: The critical role of the 2'-OH of GTP. J Biol Chem 2020; 295:12851-12867. [PMID: 32719004 DOI: 10.1074/jbc.ra120.013636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/15/2020] [Indexed: 11/06/2022] Open
Abstract
Bacterial Rel proteins synthesize hyperphosphorylated guanosine nucleotides, denoted as (p)ppGpp, which by inhibiting energy requiring molecular pathways help bacteria to overcome the depletion of nutrients in its surroundings. (p)ppGpp synthesis by Rel involves transferring a pyrophosphate from ATP to the oxygen of 3'-OH of GTP/GDP. Initially, a conserved glutamate at the active site was believed to generate the nucleophile necessary to accomplish the reaction. Later this role was alluded to a Mg2+ ion. However, no study has unequivocally established a catalytic mechanism for (p)ppGpp synthesis. Here we present a revised mechanism, wherein for the first time we explore a role for 2'-OH of GTP and show how it is important in generating the nucleophile. Through a careful comparison of substrate-bound structures of Rel, we illustrate that the active site does not discriminate GTP from dGTP, for a substrate. Using biochemical studies, we demonstrate that both GTP and dGTP bind to Rel, but only GTP (but not dGTP) can form the product. Reactions performed using GTP analogs substituted with different chemical moieties at the 2' position suggest a clear role for 2'-OH in catalysis by providing an indispensable hydrogen bond; preliminary computational analysis further supports this view. This study elucidating a catalytic role for 2'-OH of GTP in (p)ppGpp synthesis allows us to propose different mechanistic possibilities by which it generates the nucleophile for the synthesis reaction. This study underscores the selection of ribose nucleotides as second messengers and finds its roots in the old RNA world hypothesis.
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Affiliation(s)
- Pratik Rajendra Patil
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Neha Vithani
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Virender Singh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Ashok Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Balaji Prakash
- Department of Molecular Nutrition, Council of Scientific and Industrial Research-Central Food Technological Research Institute, Mysore, India.
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Jin X, Glover WJ, He X. Fragment Quantum Mechanical Method for Excited States of Proteins: Development and Application to the Green Fluorescent Protein. J Chem Theory Comput 2020; 16:5174-5188. [PMID: 32551640 DOI: 10.1021/acs.jctc.9b00980] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Understanding the excited-state properties of luminescent biomolecules is of central importance to their biophysical applications. In this study, we develop the Electrostatically Embedded Generalized Molecular Fractionation with Conjugate Caps (EE-GMFCC) method for quantitatively characterizing properties of covalently bonded systems with localized excitations (i.e., involving a single chromophore), such as fluorescent proteins. The excitation energy, transition dipole moment, and oscillator strength of wild-type Green Fluorescent Protein (wt-GFP) calculated by EE-GMFCC are found to be in excellent agreement with full system time-dependent density functional theory results. We also applied the Polarized Protein-Specific Charge model to wt-GFP, and found that electronic polarization of the protein is critical in stabilizing hydrogen bonding interactions in wt-GFP, which influences its absorption spectrum. The predicted absorption spectra of wt-GFP in the A and B states qualitatively agree with experiment. The fragmentation approach further allows a straightforward per residue decomposition of the excitation which reveals the influence of the protein environment on the absorption spectra of wt-GFP A and B states. Our results demonstrate that the EE-GMFCC method is both accurate and efficient for excited-state property calculations on proteins.
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Affiliation(s)
- Xinsheng Jin
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - William J Glover
- NYU Shanghai, 1555 Century Avenue, Shanghai 200122, China.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China.,Department of Chemistry, New York University, New York, New York 10003, United States
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
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